High speed teleconference system

ABSTRACT

A high speed teleconferencing apparatus and method, the apparatus including an encoding unit that encodes and compresses a first digital signal to produce a first compressed encoded signal, a multiplexer unit that receives and splits the first compressed encoded signal into at least two split compressed encoded signals, at least two converter units that receive a respective one of the at least two split first compressed encoded signals and respectively producing at least two first synchronous signals, and at least two output units that receive a respective one of at least two first synchronous signals and output at least two first adapted synchronous signals to a data link. The at least two output units can be, for example, two CCIT units that output at least two high speed first synchronous signals to a high speed data link. The at least two output units can also be two microwave transmitting units that respectively modulate a first microwave signal with the at least two first synchronous signals and combine the modulated signals to output a first combined microwave signal to the data link. The system can transmit information such as an audio/video signal of broadcast quality or file information via satellite to/from any location.

This application is a Continuation of application Ser. No. 08/979,546filed Nov. 26, 1997, now U.S. Pat. No. 5,903,621 which is a Continuationof application Ser. No. 08/561,168, filed Nov. 21, 1995 and now issuedas U.S. Pat. No. 5,740,214, which is a Continuation of application Ser.No. 08/047,089, filed Apr. 16, 1993, and now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to an apparatus and method fortransmitting information from one location to another and in particularto a portable satellite communications system capable of digitizing,compressing and transmitting video information from a first location,and receiving, decompressing and viewing the video signal at a secondlocation.

2. Description of Related Art

A news team frequently has to transmit a video clip of a news story atsome remote location site back to a home television station. Typically,the news team accomplishes this by either using their own earth stationwith a satellite dish and uplink electronics or renting such an earthstation from a third party. Often, however, the television stationcannot afford such an earth station or none is available from a thirdparty and consequently the news team must rely on a nearby governmentministry-owned satellite earth station.

FIG. 1A shows a truck 10 with a satellite dish 16 which together serveas a point-of-origin independent earth station 14. In order to bepoint-of-origin independent, earth station 14 must use the C or Ku-bandand, consequently, the diameter of the dish 16 must be at least 10 to 15meters. Truck 10 contains all uplink electronics required to transmitmicrowave signals in the C or Ku band. A video signal is modulated ontoa microwave signal and then is amplified and transmitted to a satellite20 typically owned by some government agency. That government agency isnot necessarily associated with the country in which the earth stationis located. The microwave signal is then downhinked to another largemicrowave dish 24 at television station 28 where it can be broadcastlive to a surrounding area or taped for broadcast at a later time.Alternatively, local television station 28 can retransmit the video clipfrom dish 24 to another television station 29 having its own dish 30with a diameter of about 8-12 feet (FIG. 1B). A local television stationcan then rebroadcast the video clip to its local viewers.

This process has a variety of drawbacks. For example, earth station 14is very large, heavy and has expensive uplink electronics. Also, earthstation 14 can weigh several tons and consequently shipping such asystem itself can become very expensive. Truck 10 with uplinkelectronics and large dish 16 can require 6 to 8 men to assemble andoperate. In addition, earth station 14 can cost several hundred thousanddollars to own, or tens of thousands of dollars to rent on a per daybasis. The process described with reference to FIG. 1A has furtherdrawbacks. For example, in order to operate earth station 14, the newsteam must obtain a license from the country in which the earth station14 is located. Since earth station 14 must be shipped to the localcountry, it also has to pass through that country's local customsoffice.

Even after all of the above drawbacks are overcome, the news team cannotsend the video clip from earth station 14 to television station 28 untilseveral more steps have been performed. First, earth station 14 mustcontact the appropriate government agency which operates satellite 20and prebook a specific time period during which the video clip will betransmitted from earth station 14 to television station 28. In addition,earth station 14 and television station 28 both must know and use theprotocol required by the particular agency or government which controlssatellite 20. Moreover, since the time of transmission via satellite 20must be prebooked, the uplink will fail if the news team does not havethe taped news clip ready. Also, despite its size and complexity, earthstation 14 does not typically contain equipment capable of editing thevideo clip before it is transmitted to television station 28 viasatellite 20.

The above scenario can be described as a "best case" scenario since itwas assumed that the television station has its own satellite dish 24and can rent or own an earth station 14. This situation becomes evenmore complicated and nearly impossible if, for example, televisionstation 28 has to rely on transmitting the video clip out of the countryeven using that country's government satellite earth station as shownFIG. 1B. In particular, FIG. 1B shows a government satellite earthstation 40 with a large C or Ku dish 44 which uplinks C or Ku microwavesto satellite 20 which in turn downlinks these microwave signals totelevision station 28.

In this scenario, transmission from earth station 40 must be prebookedwith the local government in addition to prebooking a transmission timeslot with the government or agency which operates satellite 20. (Thesetwo governments are likely not the same.) Moreover, since the localgovernment operates earth station 40, it can censor all such news clipsand allow only those news clips or sections of news clips to betransmitted with which the government agrees. Furthermore, manycountries will not have such a satellite earth station. Consequently,those television stations which do not have access to earth station 40or to an earth station similar to earth station 14 in FIG. 1A must handcarry or mail the video clip to television station 28 or to anothercountry which does have such an earth station. Hence, by the time thevideo clip arrives at television station 28, the news it contains isold.

In addition to the above difficulties associated with uplinking amicrowave signal to satellite 20, downlinking from satellite 20 totelevision station 28 may involve one or more hops as shown in FIG. 1C.In particular, FIG. 1C shows microwave signals uplinked form eitherearth station 14 or governmental earth station 40 to satellite 20 whichin turn must be downlinked (due to the location of satellite 20) to afirst earth station 50 located, for example, in Europe. First earthstation 50 must in turn uplink to a second satellite 20' which in turndownlinks to television station 28. During this process, the protocol ofeach link must be complied with. This creates an even greater burden onthe news team.

Teleconferencing technology like news gathering and broadcastingtechnology involves transmitting video signals from one location toanother. However, teleconferencing differs from news gathering in thatnews gathering typically involves transmitting high quality video imagesfrom a first location and receiving that information at a secondlocation, whereas teleconferencing involves both transmitting andreceiving video images at each of the first and second locations albeitnot necessarily video images of broadcast quality.

FIG. 2 shows a first building 200 and a second building 240interconnected via a high speed digital data network 250 such as(ACUNET) or integrated services digital network (ISDN). These networksare capable of transmitting digital information at rates of 64kilobits/second (kbps) or in some cases 128 kbps. Network 250 mustinclude a signal routing center 260 (typically owned and operated by atelephone company) and data lines 264 and 268 interconnectingteleconferencing equipment 274 in building 200 to teleconferencingequipment 278 in building 240. Signal routing center 260 can include avariety of satellite, fiber optic and standard hardwired links.

Teleconferencing equipment 274 and 278 must be capable of transmittingand receiving audio/video signals in real time. In order to do this,data lines 264 and 268 must be capable of transmitting more than thestandard telephone line audio bandwidth of 9.6 kbps. Consequently,standard telephone lines cannot be used to interconnect teleconferencingequipment 274 to teleconferencing equipment 278.

ACUNET or ISDN interconnection can transmit at high enough bit rates toenable interconnection of teleconferencing equipment. However, highspeed digital (HSD) lines or ISDN lines have been installed in only afew cities throughout the United States and only in the main businessdistricts of those cities. Moreover, only selected buildings withinthose main business districts have been hard wired with high speed datalines 264 and 268. Also, installation of such high speed data lines is along and expensive process.

SUMMARY OF THE INVENTION

An object of the invention therefore is to provide a portabletransmission system capable of transmitting information from onelocation to another.

Another object of the invention is to provide a portable transmissionsystem which can be set up quickly and easily.

Another object of the invention is to provide a portable transmissionsystem capable of receiving audio/video information from a satellite.

Another object of the invention is to provide a teleconferencing stationcapable of transmitting and receiving audio/video information.

Another object of the invention is to provide a receiving system whichis also capable of transmitting audio/video information.

Another object of the invention is to provide a transmission systemwhich can transmit a broadcast quality audio/video signal via microwavesignals without using a local earth station.

Another object of the invention is to provide a transmission systemwhich includes editing equipment for editing a video clip beforetransmission.

Another object of the invention is to be able to transmit audio/videoinformation from a remote area without having to utilize multiplesatellites, on an ad hoc, prebooked and prearranged, event-by-eventbasis.

One advantage of this system is that information can be transferredindependent of a local government's communications protocol and inmulti-satellite configurations, information is transmitted transparentlyand automatically.

Another advantage of the invention is that it utilizes over 95% of thebandwidth available in a satellite link for audio/video information and5% for overhead information as opposed to the current practice of 60% ofthe bandwidth for audio/video information and 40% of the bandwidth foroverhead.

Another advantage of the invention is that it is point-of-originindependent.

Another advantage of the invention is that it makes it possible totransmit and receive audio/video information from any place in the worldto any place in the world except possibly at the extreme polar caps.

Another advantage of the invention is that it provides transmission ofaudio/video information on an on-demand, dial-up basis.

Another advantage of the invention is that it is portable in the sensethat it can be hand carried by one person in a suitcase.

Another advantage of the invention is that it transmits high qualitytelevision pictures even with the presence of small to medium motion inthe pictures.

Another advantage of the invention is that it can multiply line ratesand feed multi-scan monitors and screens thereby dramatically improvingpicture resolution.

Another advantage of the invention is that it is compatible with highdefinition (HD) television.

Another advantage of the invention is that it can be set up and madeready to transmit within a few minutes.

Another advantage of the invention is that it can receive data from anHDS line or an ISDN line.

Another advantage of the invention is that it can operate using thepower from a single car battery to power the transmission or receivingsystem.

Another advantage of the invention is that it automatically compensatesfor color standards differences when transmitting, e.g., from PAL (theEuropean standard) to NTSC (the U.S. standard) and vice versa.

One feature of the invention is that it uses a small, fabric, microwaveumbrella dish which transmits the microwave signal on the L-band (1.5Ghz).

Another feature of the invention is that it has a built-in forward errorcorrection modem which compensates for heavy snow or rainfall blockageduring transmission.

Another feature of the invention is that it uses coding and decoding(CODEC) technology which has a very high degree of motion adaptivity andmotion compensation, thereby providing a smooth, high quality picture.

Another feature of the invention is that an analog audio/video signal isdigitized and compressed before being transmitted.

Another feature of the invention is that it uses field time visuallylossless digital data compression of an audio/video signal.

Another feature of the invention is that it includes video editingequipment for editing the audio/video signal before transmission.

Another advantage of the invention is that the transmission system caneasily be converted to a receiving system and vice versa.

Another feature of the invention is that it compresses digital videoinformation when operating as a transmission system and decompressesdigital video information when operating as a receiving system.

To achieve at least the above and other objects, advantages and featuresin whole or in parts, there is provided a high speed teleconferencestation according to the present invention that includes anencoding/compressing unit that encodes and compresses a first digitalsignal to produce a first compressed encoded signal; amultiplexing/demultiplexing unit coupled to the encoding/compressingunit that receives and splits the first compressed encoded signal intoat least two split first compressed encoded signals; at least twoconverting units, coupled to the multiplexing/demultiplexing units, thatreceive a respective one of the at least two split first compressedencoded signals and respectively produce at least two first synchronoussignals; and at least two output units each coupled to a respective oneof the at least two converting units, that receive a respective one ofthe at least two first synchronous signals, adapt and respectivelyoutput at least two adapted signals to a data link.

To further achieve the above objects, advantages and features in a wholeor in parts there is provided a high speed teleconference stationaccording to the present invention that includes an encoding/compressingunit that encodes and compresses a first digital signal to produce afirst compressed encoded signal; a multiplexing/demultiplexing unitcoupled to the encoding/compressing unit that receives and splits thefirst compressed encoded signal into at least two split first compressedencoded signals; at least two converting units, coupled to themultiplexing/demultiplexing units, that receive a respective one of theat least two split first compressed encoded signals and respectivelyproduce at least two first synchronous signals; at least two microwavetransmitter/receiver units, each coupled to a respective one of the atleast two converting units, each receiving a respective one of the atleast two first synchronous signals, generating a respective firstmicrowave signal, modulating the respective first microwave signalaccording to the respective one of the at least two first synchronoussignals to produce at least two first modulated microwave signals; and acombining/splitting unit, coupled to the at least two microwavetransmitter/receiver units, that combines the at least two firstmodulated microwave signals and outputs a first combined microwavesignal.

To further achieve the above and other objects, advantages and featuresin a whole or in parts there is provided a high speed teleconferencestation according to the present invention that includes anencoding/compressing unit that encodes and compresses a first digitalsignal to produce a first compressed encoded signal; amultiplexing/demultiplexing unit coupled to the encoding/compressingunit that receives and splits the first compressed encoded signal intoat least two split first compressed encoded signals; at least twoconverting units coupled to the multiplexing/demultiplexing unit thatreceive a respective one of the at least two split first compressedencoded signals and respectively produce at least two first synchronoussignals; and at least two CCIT units, each coupled to a respective oneof the at least two converting units that receive a respective one ofthe at least two first synchronous signals and respectively outputs atleast two high speed first synchronous signals to a high speed datalink.

To further achieve at least the above and other objects, advantages andfeatures in a whole or in parts there is provided a method fortransmitting teleconferencing information according to the presentinvention that includes encoding and compressing a first digital signalto produce a first compressed encoded signal using anencoder/compressor; splitting the first compressed encoded signal intoat least two split first compressed encoded signals using ademultiplexer; converting each of the at least two split firstcompressed encoded signals into respective at least two firstsynchronous signals using respective at least two converters; andmodifying and transmitting the at least two first synchronous signals.

To achieve at least the above and other objects, advantages and featuresof the present invention will become more apparent from the followingdescription of embodiments thereof taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B show a truck with a satellite dish which together serveas a point-of-origin independent work station and a government satelliteearth station, respectively, and FIG. 1C shows microwave signalsuplinked from either the earth station of FIG. 1A or the governmentalearth station of FIG. 1B.

FIG. 2 shows a first building and a second building connected via a highspeed digital data network such as ACUNET or ISDN.

FIGS. 3A and 3B show a transmission and receiving system according toone embodiment of the invention.

FIGS. 4A and 4B show a transmission and digital receiving systemaccording to another embodiment of the invention.

FIGS. 5A and 5B show an alternative transmission system and receivingsystem which communicate with each other via a patch unit.

FIGS. 6A and 6B show a teleconference system according to anotherembodiment of the invention.

FIGS. 7A and 7B show a teleconference system according to yet anotherembodiment of the invention.

FIG. 8 shows a high speed (128 kbps) teleconference system.

FIG. 9 shows a high speed teleconference system with a first high speedteleconference station as shown in FIG. 8 but with a second high speedteleconference station according to another embodiment of the invention.

FIG. 10A shows a suitcase for housing any one of the embodimentsdescribed above and

FIG. 10B shows the suitcase in FIG. 10A with an opened fabric microwaveumbrella dish.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 3A and 3B show a transmission and receiving system 400 accordingto one embodiment of the invention. In particular, FIG. 3A shows atransmission system 410 at a first location which communicates with areceiving system 420 at a second location via satellite 20. Throughoutthis discussion, embodiments of the invention will be described withrespect to transmitting audio/video information, it being understoodthat the invention will transmit any type of analog or digitalinformation such as digital data files, sensor signals (analog ordigital), etc.

Transmission system 410 includes an interface unit 430 which receives ananalog audio signal and an analog video signal which will be referred tohere as an analog audio/video signal and transforms the video portion ofthe analog audio/video signal into a digital red, green, blue (RGB)signal. The audio/video signal can come from a camera or a video taperecorder (VTR) neither of which is shown in the figure. Interface unit430 demodulates the audio/video signal which is either NTSC, PAL, orSECAM signal and outputs the digital RGB signal. The digital RGB signaloutput from interface unit 430 is then received by a transmit signalprocessor 440 which compresses the digital RGB signal into anasynchronous compressed signal and stores that asynchronous compressedsignal on a hard disk 440A. Transmit signal processor 440 can thenoutput the asynchronous compressed signal at high speeds using a highspeed modem (not shown). The asynchronous compressed signal is in turnreceived by a signal converter 450T which includes a protocol converter454T and a level translation unit 458T. Protocol converter 454T receivesthe asynchronous compressed signal and converts that signal to asynchronous compressed signal. The synchronous compressed signal is theninput to level translation unit 458T which swaps wires and translatesthe synchronous compressed signal voltage levels into a level translatedsynchronous compressed signal which is received by a microwavetransmitter 460T. Microwave transmitter 460T includes a modulator whichmodulates the synchronous compressed signal onto a modulated L-bandmicrowave signal. Microwave transmitter 460T then transmits themodulated L-band microwave signal to satellite 20 (which can include oneor more earth stations) which receives the L-band microwave signal andtransmits that signal to receiving system 420. In particular, microwavetransmitter 460T includes an L-band microwave generator 460A, asatellite dish 460B and a microwave modulator 460C. Satellite modem 459monitors the transmission of the modulated microwave signal frommicrowave transmitter 460T to receiving system 420. In particular,satellite modem 459 performs handshaking with receiving system 420 atthe beginning of transmission and continues to monitor the transmissionto determine whether receiving system 420 is being sent the correctsignal.

Receiving system 420 includes a microwave receiver 470 which receivesthe modulated microwave signal and demodulates that signal. Satellitemodem 472 performs handshaking with transmission system 410 in a mannersimilar to satellite modem 459. Microwave receiver 470 includes amicrowave demodulator 470C and a microwave dish 470B. A receive signalconverter 450R which includes a level translation unit 458R and aprotocol converter 454R is similar to signal converter 450T withcorresponding level translation unit 458T and protocol converter 454T,respectively. Signal converter 450R operates like signal converter 450Tused in the reverse direction. Namely, level translation unit 458Rreceives a level translated demodulated signal and translates the levelof that signal back down to asynchronous (RS-232) signal which can bereceived by protocol converter 454R and converted to an asynchronouscompressed signal. This asynchronous compressed signal is then receivedby receive signal processor 460 which decompresses it and stores it on ahard disk 460A'. If the decompression of the asynchronous compressedsignal received by receive signal processor 460 is the inverse of thecompression which the digital RGB signal underwent in transmit signalprocessor 440, receive signal processor 460 outputs that same digitalRGB signal. Consequently, the digital signal at the first location isavailable at the second location. A scan converter 464 can receive thisdigital signal and drive a studio monitor 472 via bus 468.

FIGS. 4A and 4B show a transmission system and digital receiving system500 according to another embodiment of the invention. Those elements insystem 500 which are also used in transmission and receiving system 400will be given the same reference numerals. Transmission system 410 isidentical to system 410 in system 400 of FIG. 3A. However, instead ofreceiving microwave signals from satellite 20 via microwave receiver 470as in FIG. 3A, a digital receiving system 510 receives digital data froma digital high speed data (DHSD) link 514 available from a phonecompany. Receiving system 510 includes a signal converter 550R followedby receive signal processor 460. Signal converter 550R includes leveltranslation unit 558R followed by protocol converter 454R.

The microwave signal modulated with compressed digital data is receivedby a satellite dish (here considered to be part of DHSD link 514) and inturn demodulated to yield a demodulated high speed digital (HSD) signalon DHSD line 516. DHSD link 514 includes satellite, fiber optic and hardwire links. Signal converter 550R receives the digital signal at leveltranslation unit 558R which translates its voltage level fortransmission on serial line 456R as a synchronous compressed signal.Protocol converter 454R receives and transforms the synchronouscompressed signal into an asynchronous, compressed signal fortransmission on bus 446. Receive signal processor 460 in turn receivesand decompresses the asynchronous, compressed signal into a digital RGBsignal ready to be received and converted by scan converter 464 via line462 for display via bus 468 on monitor (or VTR) 472.

FIG. 5A shows an alternative way in which transmission system 410 andreceiving system 420 can communicate with each other by using a patchunit 580. FIG. 5B shows a more detailed view of patch unit 580.Referring to FIG. 5A, transmission system 410 outputs a microwave signalwith a digitized and compressed video clip modulated onto the microwavesignal. Satellite 20 receives the microwave signal from transmissionsystem 410 and downlinks the microwave signal to a transmitting DHSDlink 514T identical to DHSD link 514 of FIG. 4A. Transmitting DHSD link514T receives the microwave signal via a satellite (not shown),transforms that signal into an HSD signal and transmits that HSD signalto patch unit 580 via line 586T. Patch unit 580 then routes that signalto a receiving line 586R. Receiving DHSD link 514R receives the HSDsignal, transforms that signal into a microwave signal and transmitsthat microwave signal back to satellite 20. Satellite 20 receives thatmicrowave signal and transmits it to receiving system 420 which receivesit and eventually outputs a digital RGB signal.

FIG. 5B shows a more detailed view of patch unit 580. Patch unit 580includes a DCU/DTE conversion unit 510T connected to a null modem 512followed by a DCU/DTE conversion unit 510R. Line 586T transmits the HSDsignal output from DHSD transmission link to DCU/DTE converter 510T andoutputs a digital signal on a V.35 pin bus 521T to null modem 512. Nullmodem 512 is wired so that both DCU/DTE converters 510T and 510R operateas if they are connected to a regular DCU modem. Null modem 512 outputsthe digital signal on V.35 pin bus 521R to DCU/DTE converter 510R whichreceives it and outputs the digital signal via 586R to DHSD link 514Rfor eventual transmission to satellite 20.

FIGS. 6A and 6B show a teleconference system 600 according to anotherembodiment of the invention. In particular, teleconference system 600includes a first teleconference station 610F at a first location and anidentical second teleconference station 610S at a second location. Firstand second teleconference stations 610F and 610S have first and seconddemodulation/converting units 630F and 630S, first and second signalprocessing units 640F and 640S, first and second satellite modems 650Fand 650S and microwave transmitter/receivers 660F and 660S,respectively. First and second microwave transmitter/receivers 660F and660S include L-band microwave generators 660FA and 660SA, satellitedishes 660FB and 660SB and microwave modulator 660FC and 660SC,respectively. First and second demodulation/converting units 630F and630S include first and second video demodulation units 631F and 631S,first and second encoding units 633F and 633S and first and second scandown converters 635F and 635S, respectively. Also, first and secondsignal processing units 640F and 640S include first and secondencoding/compression units 641F and 641S, as well as first and seconddecoding/decompression units 643F and 643S, respectively. Firstdemodulation/converting unit 630F together with first signal processingunit 640F make up a first two-way digital video processor 645F.Similarly, second demodulation/converting unit 630S together with secondsignal processing unit 640S make up a second two-way digital videoprocessor 645S.

The teleconference system operates to send a first audio/video signalfrom a first camera (not shown) to be displayed by second monitor 670Sat second teleconference station 610S while simultaneously sending asecond audio/video signal from a second camera (not shown) at secondteleconference station 610S to be displayed by first monitor 670F atfirst teleconference station 610F. Each of these processes is describedbelow.

A first analog audio/video signal is sent from first teleconferencestation 610F to second teleconference station 610S as follows. The firstanalog audio/video signal output from a first camera (not shown) at thefirst location is input to first video demodulation unit 631F. Firstvideo demodulation unit 631F then demodulates and digitizes the firstanalog audio/video signal and outputs a resulting first digital signal.The first digital signal is then input to first encoding/compressionunit 641F which can compensate for a high degree of motion, therebyproviding smoother, sharper, "non-pixelized" or jittering pictures.First encoding/compression unit 641F in turn encodes and compresses thefirst digital signal and outputs a first compressed, encoded signal. Thefirst compressed, encoded signal is then received by first microwavetransmitter/receiver 660F, which in turn modulates a first microwavesignal with the first compressed, encoded signal and transmits aresulting first modulated microwave signal to satellite 20.

Satellite 20 receives the first modulated microwave signal and outputs adownlinking modulated microwave signal having the first compressed,encoded signal modulated thereon. Second microwave transmitter/receiver660S in second teleconference station 610S receives and demodulates thisdownlinking modulated signal into the first compressed, encoded signal.Second satellite modem 650S monitors second transmitter/receiver 660S toinsure that the signal output from second microwave transmitter/receiver660S is the same as the first compressed, encoded signal which wasearlier output from first signal processing unit 640F. Secondtransmitter/receiver 660S outputs the first compressed, encoded signalto second decoding/decompression unit 643S in second signal processingunit 640S. Second decoding/decompression unit 643S demodulates anddecompresses the first encoded, compressed signal into the first digitalsignal which is the same as the first digital signal output from firstdemodulation/converting unit 630F in first teleconference station 610F.This first digital signal is then received by second encoding unit 633Sof second demodulation/converting unit 630S to be encoded into NTSC orPAL protocol for viewing on a television set (not shown). Alternatively,the first digital signal is received by second scan down converter 635Sof second demodulation/converting unit 630S which outputs a displaysignal to be viewed on second studio monitor 670S.

A second analog audio/video signal is sent from second teleconferencestation 610S to first teleconference station 610F as follows. The secondanalog audio/video signal is output from a second camera (not shown) atthe second location and input to second video demodulation unit 631S.Second video demodulation unit 631S then demodulates and digitizes thesecond analog audio/video signal and outputs a resulting second digitalsignal. The second digital signal is then input to secondencoding/compression unit 641S of second signal processing unit 640S.Second encoding/compression unit 641S in turn encodes and compresses thesecond digital signal and outputs a second compressed, encoded signal.The second compressed, encoded signal is then received by secondmicrowave transmitter/receiver 660S, which in turn modulates a secondmicrowave signal with the second compressed, encoded signal andtransmits a resulting second modulated microwave signal to satellite 20.

Satellite 20 receives the second modulated microwave signal and outputsa downlinking modulated microwave signal having the second compressed,encoded signal modulated thereon. First microwave transmitter/receiver660F in first teleconference station 610F receives and demodulates thisdownlinling modulated signal into the second compressed, encoded signal.First satellite modem 650F monitors first transmitter/receiver 660F toinsure that the signal output from first microwave transmitter/receiver660F is the same as the second compressed, encoded signal which wasearlier output from second signal processing unit 640S. Firsttransmitter/receiver 660F outputs the second compressed, encoded signalto first decoding/decompression unit 643F in first signal processingunit 640F. First decoding/decompression unit 643F demodulates anddecompresses the second encoded, compressed signal into the seconddigital signal which is the same as the second digital signal outputfrom second demodulation/converting unit 630S in second teleconferencestation 610S. This second digital signal is then received by firstencoding unit 633F of first demodulation/converting unit 630F to beencoded into NTSC or PAL protocol for viewing on a television set (notshown). Alternatively, the second digital signal is received by firstscan down converter 635F of first demodulation/converting unit 630Fwhich outputs a display signal to be viewed on first studio monitor670F.

FIGS. 7A and 7B show a teleconference system 700 according to anotherembodiment of the invention. Teleconference system 700 includesteleconference station 710 at a first location and an HSD teleconferencestation 720 at a second location. Teleconference station 710 isidentical to first or second teleconference station 610F or 610S ofteleconference system 600 in FIG. 6A. In particular, teleconferencestation 710 has a first two-way digital video processor 745F togetherwith first satellite modem 750F and first microwave transmitter/receiver760F which are identical to first two-way digital video processor 645F,first satellite modem 650F and first microwave transmitter/receiver 660Fof FIG. 6A, respectively. Also, first two-way digital video processor745F includes a first demodulation/converting unit 730F and a firstsignal processing unit 740F identical to first demodulation/convertingunit 630F and first signal processing unit 640F of FIG. 6A,respectively. Similarly, first demodulation/converting unit 730Fincludes a first video demodulation unit 731F, first encoding unit 733Fand first scan down converter 735F which are identical to first videodemodulation unit 631F, first encoding unit 633F and first scan downconverter 635F, respectively of FIG. 6A. Finally, first signalprocessing unit 740F includes first encoding/compression unit 741F, aswell as first decoding decompression unit 743F which are identical tofirst encoding/compression unit 641F, as well as firstdecoding/decompression unit 643F, respectively of FIG. 6A.

HSD teleconference station 720 is connected to a digital high speed data(DHSD) link 714 via two HSD lines 716A and 716B. HSD teleconferencestation 720 includes a second demodulation/converting unit 730S and asecond signal processing unit 740S. Second demodulation/converting unit730S includes a second video demodulation unit 731S, second encodingunit 733S and second scan down converter 735S. Second signal processingunit 740S includes second encoding/compression unit 741S and seconddecoding/decompression unit 743S.

Teleconference system 700 operates as follows. Teleconference station710 is the same as first teleconference station 610F described above.Namely, a first audio/video signal is received, processed andtransmitted from teleconference station 710 to satellite 20 the same waythat the first audio/video signal was received, processed andtransmitted from first teleconference station 610F. Also, a downlinkedmicrowave signal is received, processed and output by teleconferencestation 710 to monitor 770F (or a television or VTR) the same way thatthe downlinked microwave signal was received, processed and output byfirst teleconference station 610F to monitor 670F.

At HSD teleconference station 720, a second analog audio/video signalfrom a second camera (not shown) is input to second video demodulationunit 731S. Second video demodulation unit 731S then demodulates anddigitizes the second analog audio/video signal and outputs a resultingsecond digital signal. The second digital signal is then input to secondencoding/compression unit 741S of second signal processing unit 740S.Second encoding/compression unit 741S in turn compresses and encodes thesecond digital signal and outputs a second compressed, encoded signalwhich is sent via HSD line 716A to DHSD link 714 (which is the same asDHSD link 514 discussed with reference to FIG. 4A) to be transmitted tosatellite 20 and downlinked to teleconference station 710 as describedabove.

Satellite 20 downlinks a downlink microwave signal with the firstencoded compressed signal modulated thereon to DHSD link 714 whichreceives and demodulates it and outputs the first compressed, encodedsignal as a first demodulated high speed digital (HSD) signal on DHSDline 716B. HSD teleconference station 720 then receives the first HSDsignal and eventually outputs an analog RGB signal to second studiomonitor 770S or outputs an audio/video signal to a television (notshown) in a manner identical to second two-way digital video processor645S.

FIG. 8 shows a high speed (128 kbps) teleconference system 800 whichincludes a first high speed teleconference station 810F and a secondhigh speed teleconference station 810S. First high speed teleconferencestation 810F has a first interface unit 830F, a firstdecoding/decompression unit 841F, a first encoding/compressing unit843F, a first multiplexer 851F, two first protocol converters 855FA and855FB, two first satellite modem (demodulators) 850FA and 850FB, twofirst microwave transmitter/receivers 860FA and 860FB, a first microwavecombiner/splitter 863F and a first microwave dish 870F.

Second high speed teleconference station 810S has a second interfaceunit 830S, a second decoding/decompressing unit 841S, a secondencoding/compressing unit 843S, a second multiplexer 851S, two secondprotocol converters 855SA and 855SB, two second satellite modemdemodulators 850SA and 850SB, two second microwave transmitter/receivers860SA and 860SB, a second microwave combiner/splitter 863S and a secondmicrowave dish 870S.

Teleconference system 800 operates as follows. First high speedteleconference station 810F operates as both a transmitting andreceiving station. As a transmitting station, first high speedteleconference station 810F receives a first audio/video signal from acamera (not shown) at a first interface unit 830F which digitizes thatsignal to yield a first digital signal. First signalencoding/compression unit 843F receives the first digital signal andencodes and compresses it to yield a first compressed encoded signalwhich is asynchronous. First multiplexer 851F (used in reverse and henceserving as a demultiplexer) receives the first compressed encoded signaland splits it into first compressed encoded signals A and B which inturn are received by first protocol converters 855FA and 855FB,respectively. First protocol converters 855FA and 855FB output firstsynchronous signals A and B to first microwave transmitter/receivers860FA and 860FB, respectively. First microwave transmitter/receivers860FA and 860FB output modulated microwave signals A and B which arecombined by first combiner/splitter 863F and then output to firstmicrowave dish 870F as first modulated microwave signal A/B. Firstsatellite modem demodulators 850FA and 850FB insure that the signalsoutput from first microwave transmitter/receiver 860FA and 860FB are thesame as the signals received by second microwave transmitter/receivers860SA and 860SB, respectively. Second high speed teleconference station810S operates in an analogous manner when transmitting a secondmodulated microwave signal A/B to be received by first high speedteleconference station 810F.

As a receiving station, first satellite dish 870F of first high speedteleconference station 810F receives a second modulated microwave signalA/B which is split (since they are traveling right to left in FIG. 8) byfirst combiner/splitter 863F. First microwave transmitter/receivers860FA and 860FB receive second modulated microwave signals A and B anddemodulate these second modulated microwave signals A and B to yieldresulting second synchronous signals A and B, respectively. Firstprotocol converters 855FA and 855FB in turn output second compressedencoded signals A and B which are combined by first multiplexer 851F toyield a second compressed encoded signal. First decoding/decompressionunit 841F decompresses and decodes the second compressed encoded signaland outputs a second audio/video signal which can be viewed on atelevision monitor (not shown). Second high speed teleconference station810S operates in an analogous manner when receiving the first modulatedmicrowave signal A/B from first high speed teleconference station 810F.

FIG. 9 shows a high speed teleconference system 900 with a high speedteleconference station 910 which is analogous to first high speedteleconference station 810F as in FIG. 8 but with a second high speedteleconference station 920 according to another embodiment of theinvention. Those elements in FIG. 9 common to FIG. 8 have been givensimilar reference numbers. For example, high speed teleconferencestation 910 is the same as first high speed teleconference station 810Fin FIG. 8. HSD teleconference station 920 has a second interface unit930S, a second signal decoding/decompression unit 941S, a second signalencoding/compression unit 943S, two second protocol converters 955SA and955SB and CCIT 261 units 925A and 925B. As can be seen however, HSDteleconference station 920 does not have second satellite modemdemodulators 850SA and 850SB, second microwave transmitter/receivers860SA and 860SB, a second microwave combiner/splitter 863S or a secondmicrowave dish 870S as shown in second high speed teleconference station810S of FIG. 8. Instead, HSD teleconference station 920 is coupled to anHSD link 914 similar to HSD links 514 and 714 in FIGS. 4A and 7A,respectively. A line doubler and enhancer can be used to enhance aresulting "soft" picture signal output from second interface unit 930S.This signal can be passed on to a multi-scan (high density televisioncapable) monitor (not shown).

HSD teleconference station 920 operates in the same manner as secondhigh speed teleconference station 810S in transmitting secondsynchronous signals A and B from second protocol converters 855SA and855SB and in receiving first synchronous signal A and B from first highspeed teleconference station 810F. Here, however, CCIT units 925A and925B each receives a 64 bps HSD signal from HSD link 914. CCIT units925A and 925B in turn output the first synchronous signals A and B totwo second protocol converters 955SA and 955SB, respectively.

Hardware Implementation

Various embodiments of the invention have been repeatedly tested atCOMSAT headquarters at 810 L'Enfant Plaza, Washington, D.C., using thefollowing equipment.

A DigitalFilm break out box made by SuperMac can be used to break downcomposite video to component video i.e., RGB signals, and consequentlycan serve as video demodulation units 631F, 631S, 731F and 731S. AnEmotia converter can be used to down convert from high frequencycomputer display domain to analog studio RGB domain and consequently canserve as scan down converters 464, 635F, 635S, 735F and 735S. An NTLencoder takes an RGB computer domain signal and converts to lowestcommon denominator monitoring and/or recording, i.e., composite video,and consequently can serve as encoding units 633F, 633S, 733F and 733S.Motion J-PEG or AM-PEG compression chips by C-Cubed used with a SuperMacand Macintosh hardware/software package and a 2 Gigabyte dual array harddisk drive provides visually lossless high compression ratios forunmanaged full motion video and consequently can serve as transmitsignal processor 440 and receive signal processor 460.

As data enters from the computer domain to the rf communicationarchitecture in the real world, the status of the data must be changedfrom asynchronous data to synchronous data and the electrical propertiesof connector pins associated with the transport of the signal must bechanged accordingly. Both AM-PEG and J-PEG compression require leveltranslation. However, J-PEG also requires state conversion of databetween asynchronous and synchronous conversion, whereas AM-PEG dataalthough asynchronous, is easily modified to become synchronous.

Black Box Model ASI-IV Protocol Converter changes asynchronous dataterminal equipment (DTE) to communicate over a synchronous communicationline. This converter allows asynchronous devices like terminals, PCs,and midrange computers to communicate using synchronous modems ormultiplexers and consequently can serve as protocol converter 454T,454R. RS-232 to V.35 Interface Converter by Black Box providesbi-directional conversion of all commonly used V.35 (synchronous world)and RS-232 (asynchronous world) equipment. The unit is designed for useas one port configured as DTE and the other port as DCE and consequentlycan serve as interface units 430, 830F, 830S, 930F and 930S. Also, BlackBox ASI-IV Protocol Converter together with RS-232 to V.35 InterfaceConverter can serve as signal converters 450T, 855FA, 855FB, 855SA,855SB, 955FA, 955FB, 955SA and 955SB.

TCS-9700 by Mobile Telesystems, Inc. in its full duplex high speed dataconfiguration can serve as microwave transmitter 460T, microwavereceiver 470, microwave transmitter/receivers 660F, 660S, 760S, 860FA,860FB, 860SA, 860SB. The TCS-9700 includes a transmit modem formodulating a microwave signal to provide an uplink data stream.

COMSAT owns and operates earth stations for international L-Band basedsatellite communications and Inmarsat owns and operates a string ofsatellites circling the earth which provides on demand high speed datachannels for registered users. These channels are charged to a user on atime basis much like telephone lines for telephones.

COMSAT and Inmarsat provide a duplex high speed data microwave channelwhich requires a demodulator to effectuate a handshake and qualitycontrol (feedback). A Comstream Model 701 satellite modem completes theduplex architecture by acting as a demodulator and consequently canserve as satellite modems 459, 472, 650F, 650S, 750F, 850FA, 850FB,850SA, 850SB, 950FA and 950FB.

A Compression Labs Inc. (CLI) device model Eclipse compresses anddecompresses low and medium motion managed video with motioninterpolation buffering to give a naturalness to motion and speechindistinguishable from real life and consequently can serve as CCITunits 925A, 925B. This results in a "soft" picture which can be"sharpened" or enhanced by line doubling. National TranscommunicationsLabs PAL/NTSC to HDTV Converter provides line doubling to create addeddetail and consequently can serve as line doubling and enhancer. Thesignal output from line doubling and enhancer can be passed on to amulti-scan (high density television capable) monitor.

Null modem 512 swaps wires so that "send" goes to "receive" and"receive" goes to "send" to allow transparent full duplexcommunications. Any standard null modem can accomplish this. DCU/DTEunits 510R, 510T are provided by the telephone company in the region inwhich patch unit 580 is located.

"Digital Film, Professional Video Editing Studio in a Box" User Manual,SuperMac Technology, Inc., 1992, is incorporated herein by reference."Macintosh User's Guide, for desktop Macintosh computers," AppleComputer, Inc., 1992, is incorporated herein by reference. "AdobePremiere, User Guide," Adobe Systems, Inc., 1992, is incorporated hereinby reference. "ASI-IV," January 1992, IC556A and IC556AE is incorporatedherein by reference. "RS-232 V.35 Interface Converter," IC221A-R2, byBlack Box Corporation, August 1992, is incorporated herein by reference."Model TCS-9700 Transportable Communications System, Operator's Manual"by Mobile Telesystems, Inc., Document 203890B, Dec. 24th, 1992, isincorporated herein by reference. Chapter 2 of "CM701 PSK Digital ModemOperator's Manual," by ComStream is incorporated herein by reference.

FIG. 10A shows a suitcase 1001 having a length L, width W and height Hfor housing any one of the embodiments described above and FIG. 10Bshows suitcase 1001 with an opened fabric microwave umbrella dish 1002.In particular, FIG. 10A shows suitcase 1001 having a bottom portion1004, a lid 1006 and a handle 1008. The length L, width W and height Hof suitcase 1001 housing the above embodiments has been made smallerthan 25 by 24.5 and 16 inches, respectively. Suitcase 1001 is lightenough that a person of average strength can easily carry it by handle1008. That is, all of the above embodiments can be housed in suitcase1001 and consequently are portable.

FIG. 10B shows suitcase 1001 with opened umbrella dish 1002. Microwaveumbrella dish 1002 has a diameter of about 1.2 meters when opened. FIG.10B shows umbrella dish 1008 to be slanted at an elevation angle E andready to transmit and/or receive microwave signals.

Numerous and additional modifications and variations of the presentinvention are possible in light of the above teachings. It is thereforeto be understood that within the scope of the appended claims, theinvention may be practiced otherwise as specifically claimed.

What is claimed is:
 1. A high speed teleconference station comprising:anencoding/compressing unit that encodes and compresses a first digitalsignal to produce a first compressed encoded signal; amultiplexing/demultiplexing unit coupled to said encoding/compressingunit that receives and splits said first compressed encoded signal intoat least two split first compressed encoded signals; at least twoconverting units, coupled to said multiplexing/demultiplexing units,that receive a respective one of said at least two split firstcompressed encoded signals and respectively produce at least two firstsynchronous signals; and at least two output units, each coupled to arespective one of said at least two converting units, that receive arespective one of said at least two first synchronous signals, adapt andrespectively output at least two adapted signals to a data link.
 2. Thehigh speed teleconference station of claim 1, wherein the at least twooutput units are microwave transmitter/receiver units, each generating arespective first microwave signal, modulating said respective firstmicrowave signal according to said respective one of said at least twofirst synchronous signals to produce at least two first modulatedmicrowave signals, further comprisinga combining/splitting unit, coupledto said at least two microwave transmitter/receiver units, that combinessaid at least two first modulated microwave signals and outputs a firstcombined microwave signal to the data link.
 3. The high speedteleconference station of claim 1, wherein the at least two output unitsare CCIT units that respectively output at least two high speed firstsynchronous signals to the data link.
 4. The high speed teleconferencestation of claim 1, further comprising an interface unit that receives afirst analog signal and outputs the first digital signal, wherein saidfirst analog signal is audio and video for teleconferencing.
 5. The highspeed teleconference station of claim 1, further comprising a housingunit that houses said multiplexing/demultiplexing units, said at leasttwo converting units, said at least two output units and said interfaceunit.
 6. A high speed teleconference station comprising:anencoding/compressing unit that encodes and compresses a first digitalsignal to produce a first compressed encoded signal; amultiplexing/demultiplexing unit coupled to said encoding/compressingunit that receives and splits said first compressed encoded signal intoat least two split first compressed encoded signals; at least twoconverting units, coupled to said multiplexing/demultiplexing units,that receive a respective one of said at least two split firstcompressed encoded signals and respectively produce at least two firstsynchronous signals; at least two microwave transmitter/receiver units,each coupled to a respective one of said at least two converting units,each receiving a respective one of said at least two first synchronoussignals, generating a respective first microwave signal, modulating saidrespective first microwave signal according to said respective one ofsaid at least two first synchronous signals to produce at least twofirst modulated microwave signals; and a combining/splitting unit,coupled to said at least two microwave transmitter/receiver units, thatcombines said at least two first modulated microwave signals and outputsa first combined microwave signal.
 7. The high speed teleconferencestation of claim 6, further comprising a housing unit that houses saidmultiplexing/demultiplexing units, said at least two converting units,said at least two microwave transmitter/receiver units, and saidcombining/splitting unit.
 8. The high speed teleconference station ofclaim 6, wherein said at least two converting units each include aprotocol converter and an interface converter, wherein said interfaceconverter is an RS-232 to V.35 interface converter, and wherein saidencoding/compressing unit uses motion interpolation buffering.
 9. Thehigh speed teleconference station of claim 6, wherein:saidcombining/splitting unit receives a second combined microwave signal andoutputs at least two second modulated microwave signals; said at leasttwo microwave transmitter/receiver units each receive a respective oneof said at least two second modulated microwave signals and outputs arespective one of at least two second synchronous signals; said at leasttwo converting units each receive a respective one of said at least twosecond synchronous signals and respectively produces at least two splitsecond compressed encoded signals; and said multiplexing/demultiplexingunit receives and combines said at least two split second compressedencoded signals into a second compressed encoded signal.
 10. The highspeed teleconference station of claim 9, further comprising:adecoding/decompressing unit coupled to said multiplexing/demultiplexingunit that receives said second compressed encoded signal and produces asecond digital signal; and at least two modems, each coupled between arespective one of said at least two microwave transmitter/receiver unitsand a respective one of said at least two converting units.
 11. A highspeed teleconference station comprising:an encoding/compressing unitthat encodes and compresses a first digital signal to produce a firstcompressed encoded signal; a multiplexing/demultiplexing unit coupled tosaid encoding/compressing unit that receives and splits said firstcompressed encoded signal into at least two split first compressedencoded signals; at least two converting units coupled to saidmultiplexing/demultiplexing unit that receive a respective one of saidat least two split first compressed encoded signals and respectivelyproduce at least two first synchronous signals; and at least two CCITunits, each coupled to a respective one of said at least two convertingunits, receives a respective one of said at least two first synchronoussignals and respectively outputs at least two high speed firstsynchronous signals to a high speed data link.
 12. The high speedteleconference station of claim 11, wherein:said at least two CCIT unitseach receives a respective one of at least two high speed secondsynchronous signals from the high speed data link and respectivelyproduces at least two second synchronous signals; said at least twoconverting units each receives a respective one of said at least twosecond synchronous signals and respectively produces at least two splitsecond compressed encoded signals; and said multiplexing/demultiplexingunit receives and combines said at least two split second compressedencoded signals into a second compressed encoded signal.
 13. The highspeed teleconference station of claim 11, further comprising:aninterface unit that receives a first analog signal and outputs the firstdigital signal; a decoding/decompressing unit, coupled to saidmultiplexing/demultiplexing unit, that receives said second compressedencoded signal and produces a second digital signal; and a housing unitthat houses said interface unit, said encoding/compressing unit, saidmultiplexing/demultiplexing unit, said at least two converting units,said at least two CCIT units, and said decoding/decompressing unit. 14.A method for transmitting teleconferencing information comprising thesteps of:encoding and compressing a first digital signal to produce afirst compressed encoded signal using an encoder/compressor; splittingsaid first compressed encoded signal into at least two split firstcompressed encoded signals using a demultiplexer; converting each ofsaid at least two split first compressed encoded signals into respectiveat least two first synchronous signals using respective at least twoconverters; and modifying and transmitting said at least two firstsynchronous signals.
 15. The method for transmitting teleconferencinginformation of claim 14, wherein said step of modifying and transmittingcomprises:producing respective at least two first high speed synchronoussignals for said at least two first synchronous signals using respectiveat least two CCIT devices; and transmitting said at least two high speedfirst synchronous signals to a high speed data link.
 16. The method fortransmitting teleconferencing information of claim 14, wherein said stepof modifying and transmitting comprises:generating a respectivemicrowave signal using a respective one of at least two microwavetransmitter/receiver units; modulating said respective microwave signalaccording to said respective ones of said at least two first synchronoussignals to produce at least two first modulated microwave signals usingsaid at least two microwave transmitter/receiver units; and combiningsaid at least two first modulated microwave signals using acombining/splitting unit to produce a combined first microwave signaland outputting the combined first microwave signal.
 17. The method ofclaim 14, further comprising the steps of:receiving at least two secondsynchronous signals; converting said at least two second synchronoussignals to respective at least two split second compressed encodedsignals; combining said at least two split second compressed encodedsignals into a second compressed encoded signal using a multiplexer; anddecoding and decompressing said second compressed encoded signal toproduce a second digital signal.
 18. The method of receivingteleconferencing information of claim 17, wherein said receiving atleast two second synchronous signals comprises:receiving two high speedsecond synchronous signals from a high speed data link; and producingsaid respective two second synchronous signals from said two high speedsecond synchronous signals.
 19. The method for receivingteleconferencing information of claim 17, wherein said receiving atleast two second synchronous signals comprises:receiving a combinedsecond microwave signal; splitting said combined second microwave signalusing a combining/splitting unit to produce two second modulatedmicrowave signals; and receiving said two second modulated microwavesignals using at least two microwave transmitter/receiver units andoutputting said two second synchronous signals.